Need to Escape Jupiter’s Gravitational Pull? Good Luck

Randall of xkcd has been having fun with data visualization lately. In his latest data-ish comic, Randall explores gravity wells. The height of each well is sized relative to the amount of energy (on Earth) it would take to escape that planet’s gravity. The width of wells are scaled by planet size.

So you’d need one big arse rocket to escape Jupiter.

I know it’s a comic, hand-drawn, and all stick-figurey and stuff, but Randall actually explains the concepts really well. There’s good annotation, clear examples, and he’s made an obscure topic easy to understand.

It’s also entertaining in the Bill Nye the Science Guy (i.e. best Saturday morning show ever) sort of way.

Just gotta say that the ‘(on Earth)’ notation is incorrect. In fact, the amount of energy needed to escape, say, Europa’s gravity well is most explicitly not ‘on Earth’.

You may be thinking of mass -> weight conversions… ie, if something with a mass of 1 kilogram is on Earth, it presses down with a force of 9.8 Newtons, but with a different force on other planets. This is unrelated to the xkcd chart, and the gravity wells simply indicate energy required to escape them… and that energy has nothing to do with Earth’s gravity well.